Fix more minor mode docstrings.

Fix more minor mode docstrings.

* lisp/emulation/cua-base.el (cua-mode):
* lisp/mail/footnote.el (footnote-mode):
* lisp/mail/mailabbrev.el (mail-abbrevs-mode):
* lisp/net/xesam.el (xesam-minor-mode):
* lisp/progmodes/bug-reference.el (bug-reference-mode):
* lisp/progmodes/cap-words.el (capitalized-words-mode):
* lisp/progmodes/compile.el (compilation-minor-mode)
(compilation-shell-minor-mode):
* lisp/progmodes/gud.el (gud-tooltip-mode):
* lisp/progmodes/hideif.el (hide-ifdef-mode):
* lisp/progmodes/idlw-shell.el (idlwave-shell-electric-debug-mode):
* lisp/progmodes/subword.el (subword-mode):
* lisp/progmodes/vhdl-mode.el (vhdl-electric-mode, vhdl-stutter-mode):
* lisp/progmodes/which-func.el (which-function-mode):
* lisp/term/tvi970.el (tvi970-set-keypad-mode):
* lisp/term/vt100.el (vt100-wide-mode):
* lisp/textmodes/flyspell.el (flyspell-mode):
* lisp/textmodes/ispell.el (ispell-minor-mode):
* lisp/textmodes/nroff-mode.el (nroff-electric-mode):
* lisp/textmodes/paragraphs.el (use-hard-newlines):
* lisp/textmodes/refill.el (refill-mode):
* lisp/textmodes/reftex.el (reftex-mode):
* lisp/textmodes/rst.el (rst-minor-mode):
* lisp/textmodes/sgml-mode.el (html-autoview-mode)
(sgml-electric-tag-pair-mode):
* lisp/textmodes/tex-mode.el (latex-electric-env-pair-mode):
* lisp/vc/diff-mode.el (diff-auto-refine-mode, diff-minor-mode):
* lisp/emulation/crisp.el (crisp-mode):
* lisp/emacs-lisp/eldoc.el (eldoc-mode):
* lisp/emacs-lisp/checkdoc.el (checkdoc-minor-mode): Doc fixes for new
minor mode behavior.

* lisp/erc/erc-fill.el (erc-fill-mode):
* lisp/erc/erc-track.el (erc-track-minor-mode): Doc fix.

* lisp/erc/erc.el (define-erc-module): Fix autogenerated docstring to
reflect Emacs 24 minor mode changes.

* lisp/gnus/gnus-cite.el (gnus-message-citation-mode): Doc fix (in Emacs 24,
calling a minor mode from Lisp with nil arg enables it, so we have to
make the working a bit ambiguous here).